我实现了以下方法和单元测试:
use std::fs::File;
use std::path::Path;
use std::io::prelude::*;
fn read_file(path: &Path) {
let mut file = File::open(path).unwrap();
let mut contents = String::new();
file.read_to_string(&mut contents).unwrap();
println!("{}", contents);
}
#[test]
fn test_read_file() {
let path = &Path::new("/etc/hosts");
println!("{:?}", path);
read_file(path);
}
我以这样的方式运行单元测试:
rustc --test app.rs; ./app
我也可以运行这个
cargo test
我得到一条消息，说测试通过了，但是println!永远不会显示在屏幕上。为什么不呢?
博士TL;
$ cargo test -- --nocapture
使用以下代码:
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
pub enum PieceShape {
King, Queen, Rook, Bishop, Knight, Pawn
}
fn main() {
println!("Hello, world!");
}
#[test]
fn demo_debug_format() {
let q = PieceShape::Queen;
let p = PieceShape::Pawn;
let k = PieceShape::King;
println!("q={:?} p={:?} k={:?}", q, p, k);
}
然后执行如下命令:
$ cargo test -- --nocapture
你们应该看到
Running target/debug/chess-5d475d8baa0176e4
running 1 test
q=Queen p=Pawn k=King
test demo_debug_format ... ok
test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured
